The U.N. Committee on the Rights of the Child cites reports that U.S. forces killed hundreds of Afghan children in the last four years, which the U.S. calls 'categorically unfounded.'

KABUL, Afghanistan — The U.S. military Friday strongly rejected reports cited by a United Nations committee indicating that American forces had killed hundreds of children in Afghanistan over the last four years.

The U.N. Committee on the Rights of the Child said it was alarmed by reports that hundreds of children had died in U.S. attacks and airstrikes due to a "reported lack of precautionary measures and indiscriminate use of force."

The U.S. military called the reports "categorically unfounded."

The U.N. committee stated its concern last week in a response to a periodic report by the United States on measures it had taken to protect children in armed conflict. The committee also expressed concern that "members of the armed forces responsible for the killings of children have not always been held accountable."

In a statement, the U.S. military said the reports were unsubstantiated and cited figures from the U.N. Assistance Mission in Afghanistan showing that the vast majority of civilian deaths and injuries in Afghanistan over the last several years were caused by insurgents.

The Geneva-based U.N. committee, which is independent of the U.N. mission in Afghanistan, was reviewing U.S. policies on children in conflict for the first time since 2008. In addition to the Afghan mission's figures, it received information from several international rights groups, including New York-based Human Rights Watch.

In April, U.N. Secretary-General Ban Ki-moon said that 110 children were killed and 68 were injured in 2011 in airstrikes conducted by pro-government forces, led by the United States, which furnishes air power for the Afghan government. Those figures represented a doubling of the child casualties from a year earlier, Ban said.

But the U.S. military said that the International Security Assistance Force, which it leads, reduced civilian casualties by 49% in 2012 from 2011, and that the number of children killed or wounded in ISAF air operations fell by nearly 40%.

The military rejected the allegation that it used force indiscriminately, saying it applies strict rules when carrying out airstrikes in areas where civilians may be. When their operations do kill civilians, "ISAF and U.S. military officials make every effort to meet with the families of those we have harmed and to express our condolences personally," the statement said.

Advocacy groups praised the U.N. committee's findings and called on the United States to do more to protect children on the battlefield.

"The U.S. must also honor its international law obligations to thoroughly and independently investigate civilian deaths and abuses against children, hold perpetrators accountable and compensate victims," Jamil Dakwar, director of the American Civil Liberties Union's Human Rights Program, told the Associated Press.